Observer pattern - golang

interface.go

// Observable ...
type Observable interface{}

// Callback ...
type Callback func(Observable)

// Human ...
type Human struct {
	name string
}

// Alien ...
type Alien struct {
	ooo string
}

main.go

package main

import "fmt"
 
func main() {
	human := &Alien{ooo: "Jack"}
	humanObserver := Observer{}

	humanObserver.Add(callName)
	humanObserver.Process(human)
}

func callName(o Observable) {
	human, ok := o.(*Human)
	if !ok {
		return
	}

	fmt.Println(human.name)
}

observer.go

// Observer ...
type Observer struct {
	callbacks []Callback
}

// Add ...
func (o *Observer) Add(c Callback) {
	o.callbacks = append(o.callbacks, c)
}

// Process ...
func (o Observer) Process(value Observable) {
	for _, callback := range o.callbacks {
		callback(value)
	}
}